Benefits of Aspirin Are Underestimated for Recurrent Stroke

Taking aspirin immediately after a transient ischemic attack (TIA) or ischemic stroke reduces the 2-week risk of having another stroke by 93%, according to a recent study.

Previous studies have found that taking aspirin after an initial TIA or ischemic stroke reduces the risk of recurrent stroke by only 13%. However, the highest risk for a second event only lasts for a few days after the first event. Therefore, the researchers hypothesized that the short-term benefits of an aspirin regimen have been underestimated.
_________________________________________________________________________________________________________________________________________________________________________

To conduct their study, the researchers pooled data from 15,778 participants in 12 randomized trials of aspirin vs control in secondary prevention after an initial TIA or ischemic stroke.

The researchers also studied the effects of aspirin on the risk and severity of recurrent stroke less than 6 weeks, 6 to 12 weeks, and more than 12 weeks after randomization.

After analyzing the data, the researchers found that aspirin reduced the risk of 2-week recurrent stroke by 93%. It also reduced the 6-week risk of recurrent ischemic stroke by 60% and disabling or fatal ischemic stroke by 70%. The 6-to-12-week risk was further reduced, but no benefit was seen after 12 weeks.

“Our findings confirm that medical treatment substantially reduces the risk of early recurrent stroke after TIA and minor stroke and identify aspirin as the key intervention,” the researchers concluded.

“The considerable early benefit from aspirin warrants public education about self-administration after possible TIA. The previously unrecognised effect of aspirin on severity of early recurrent stroke, the diminishing benefit with longer-term use, and the contrasting time course of effects of dipyridamole have implications for understanding mechanisms of action.”

—Amanda Balbi

Reference:

Rothwell PM, Algra A, Chen Z, Diener HC, Norrving B, Mehta Z. Effects of aspirin on risk and severity of early recurrent stroke after transient ischaemic attack and ischaemic stroke: time-course analysis of randomised trials [published online May 18, 2016]. Lancet.  dx.doi.org/10.1016/S0140-6736(16)30468-8.